archive/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2025-08-28 15:24:43 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

8207343: Automate vtable/itable stub size calculation

Browse source 
Reviewed-by: kvn, mdoerr
This commit is contained in:
Lutz Schmidt 2018-09-03 09:43:08 +02:00
parent d08c6c824d
commit f36874335d
10 changed files with 717 additions and 679 deletions
Download patch file Download diff file Expand all files Collapse all files

102
src/hotspot/share/code/vtableStubs.cpp
View file

@ -92,6 +92,32 @@ void VtableStub::print_on(outputStream* st) const {
VtableStub* VtableStubs::_table[VtableStubs::N];
int VtableStubs::_number_of_vtable_stubs = 0;
int VtableStubs::_vtab_stub_size = 0;
int VtableStubs::_itab_stub_size = 0;
#if defined(PRODUCT)
// These values are good for the PRODUCT case (no tracing).
static const int first_vtableStub_size = 64;
static const int first_itableStub_size = 256;
#else
// These values are good for the non-PRODUCT case (when tracing can be switched on).
// To find out, run test workload with
// -Xlog:vtablestubs=Trace -XX:+CountCompiledCalls -XX:+DebugVtables
// and use the reported "estimate" value.
// Here is a list of observed worst-case values:
// vtable itable
// aarch64: 460 324
// arm: ? ?
// ppc (linux, BE): 404 288
// ppc (linux, LE): 356 276
// ppc (AIX): 416 296
// s390x: 408 256
// Solaris-sparc: 792 348
// x86 (Linux): 670 309
// x86 (MacOS): 682 321
static const int first_vtableStub_size = 1024;
static const int first_itableStub_size = 512;
#endif
void VtableStubs::initialize() {
@ -107,6 +133,77 @@ void VtableStubs::initialize() {
}
int VtableStubs::code_size_limit(bool is_vtable_stub) {
if (is_vtable_stub) {
return _vtab_stub_size > 0 ? _vtab_stub_size : first_vtableStub_size;
} else { // itable stub
return _itab_stub_size > 0 ? _itab_stub_size : first_itableStub_size;
}
} // code_size_limit
void VtableStubs::check_and_set_size_limit(bool is_vtable_stub,
int code_size,
int padding) {
const char* name = is_vtable_stub ? "vtable" : "itable";
guarantee(code_size <= code_size_limit(is_vtable_stub),
"buffer overflow in %s stub, code_size is %d, limit is %d", name, code_size, code_size_limit(is_vtable_stub));
if (is_vtable_stub) {
if (log_is_enabled(Trace, vtablestubs)) {
if ( (_vtab_stub_size > 0) && ((code_size + padding) > _vtab_stub_size) ) {
log_trace(vtablestubs)("%s size estimate needed adjustment from %d to %d bytes",
name, _vtab_stub_size, code_size + padding);
}
}
if ( (code_size + padding) > _vtab_stub_size ) {
_vtab_stub_size = code_size + padding;
}
} else { // itable stub
if (log_is_enabled(Trace, vtablestubs)) {
if ( (_itab_stub_size > 0) && ((code_size + padding) > _itab_stub_size) ) {
log_trace(vtablestubs)("%s size estimate needed adjustment from %d to %d bytes",
name, _itab_stub_size, code_size + padding);
}
}
if ( (code_size + padding) > _itab_stub_size ) {
_itab_stub_size = code_size + padding;
}
}
return;
} // check_and_set_size_limit
void VtableStubs::bookkeeping(MacroAssembler* masm, outputStream* out, VtableStub* s,
address npe_addr, address ame_addr, bool is_vtable_stub,
int index, int slop_bytes, int index_dependent_slop) {
const char* name = is_vtable_stub ? "vtable" : "itable";
const int stub_length = code_size_limit(is_vtable_stub);
if (log_is_enabled(Trace, vtablestubs)) {
log_trace(vtablestubs)("%s #%d at " PTR_FORMAT ": size: %d, estimate: %d, slop area: %d",
name, index, p2i(s->code_begin()),
(int)(masm->pc() - s->code_begin()),
stub_length,
(int)(s->code_end() - masm->pc()));
}
guarantee(masm->pc() <= s->code_end(), "%s #%d: overflowed buffer, estimated len: %d, actual len: %d, overrun: %d",
name, index, stub_length,
(int)(masm->pc() - s->code_begin()),
(int)(masm->pc() - s->code_end()));
assert((masm->pc() + index_dependent_slop) <= s->code_end(), "%s #%d: spare space for 32-bit offset: required = %d, available = %d",
name, index, index_dependent_slop,
(int)(s->code_end() - masm->pc()));
// After the first vtable/itable stub is generated, we have a much
// better estimate for the stub size. Remember/update this
// estimate after some sanity checks.
check_and_set_size_limit(is_vtable_stub, masm->offset(), slop_bytes);
s->set_exception_points(npe_addr, ame_addr);
}
address VtableStubs::find_stub(bool is_vtable_stub, int vtable_index) {
assert(vtable_index >= 0, "must be positive");
@ -173,10 +270,7 @@ VtableStub* VtableStubs::entry_point(address pc) {
uint hash = VtableStubs::hash(stub->is_vtable_stub(), stub->index());
VtableStub* s;
for (s = _table[hash]; s != NULL && s != stub; s = s->next()) {}
if (s == stub) {
return s;
}
return NULL;
return (s == stub) ? s : NULL;
}
bool VtableStubs::contains(address pc) {